IRRADIATION SPECIFICATIONS

ObjectivesTo search for more effective radiation protectors with minimal toxicity, a water-soluble nitroxides Acetamido-Tempol (AA-Tempol) was evaluated for potential radioprotective properties in HUVEC cells (Human Umbilical Vein Endothelial cell line).MethodsTo study the anti-radiation effect of AA-Tempol in cell culture, the viability of irradiated HUVEC cells using a clonogenic survival assay was examined. The anti-apoptosis effects of AA-Tempol using Annexin V/propidium iodide staining in a flow cytometry assay was also evaluated. To elucidate the molecular mechanism of the anti-apoptosis effect of AA-Tempol against X-radiation induced HUVEC cell apoptosis, the expression of Bax, Bcl-2 and p53 and caspase-3 were examined. The changes in the level of malondialdehyde (MDA) and glutathione (GSH) in HUVEC cells after X-radiation were also investigated.ResultsPretreatment of the HUVEC cells colony with AA-Tempol 1 h before X-radiation significantly increased the colony survival (p < 0.05) compared with the cells without pretreatment. This demonstrates that AA-Tempol provides an effective radiation protection in the irradiated HUVEC cells, thus reducing apoptosis from 20.1 ± 1.3% in 8 Gy X-radiated cells to 12.2 ± 0.9% (1.0 mmol/L−1 AA-Tempol) in AA-Tempo pretreated HUVEC cells. This implies that 1.0 mM AA-Tempol treatment significantly block the increase of caspase-3 activity in radiated HUVEC cells (P < 0.01), causing down-regulation in expressions of Bax and P53 and up-regulation in the expression of Bcl-2. Pretreatment with AA-Tempol also decreased the MDA activities (P < 0.01) and increase the GSH level (P < 0.05) in HUVEC cells compared to the 8Gy X-radiated cells without pretreatment.ConclusionsThese observations indicate that AA-Tempol is a potential therapeutic agent against the radiation damage.

Electrons are an important constituent part of radiation space of charged particles and could damage microelectronic devices. Therefore, effective radiation protection is very important for the electronic device. So, a radiation protecting material with lightweight, high performance and low cost is urgently needed. Polyethylene (PE) with high hydrogen content/carbon nanotube (CNT) composite as a space shielding material is very promising for spacecraft application in the future. In order to meet the requirement of space applications for PE/CNT composite, it is of important academic value and practical significance to explore melting and crystallization behaviors of LDPE/MWCNT composites. In this paper, melting and crystallization behaviours of the irradiated LDPE/MWCNT composites irradiated by 110 keV electrons are studied by differential scanning calorimetry (DSC), synchrotron radiation X-ray small angle scattering (SAXS) and wide angle diffraction (WAXD). Experimental results show that the irradiation by 110 keV electrons does not affect the thermal characteristics of the LDPE, but can enhance the initial melting temperature and the melting-terminating temperature of LDPE/2% MWCNT composites during melting. Also, the radiation by 110 keV electrons could reduce the initial crystallization temperature and the crystallization-terminating temperature during crystallization. MWCNTs could enhance the initial melting temperature and reduce the melting-terminating temperature of LDPE/2% MWCNT composites during melting. Moreover, MWCNTs could enhance the initial crystallization temperature and crystallinity, and reduce the crystallization-terminating temperature during crystallization. SAXS and WAXD analyses show that with increasing the temperature, long periods of the irradiated/unirradiated LDPE increase during melting. Compared with that of the unirradiated LDPE, at a given temperature, long period of the irradiated LDPE is small. During crystallization, with reducing the temperature, long period of the irradiated/unirradiated LDPE begins to appear and gradually decreases. At the same temperature, long period of the irradiated LDPE is larger than that of the unirradiated one. For LDPE/2% MWCNT composites, long periods of the irradiated/unirradiated samples during melting and crystallization do not exist. The 110 keV electron irradiation mainly influences LDPE matrix of LDPE/2% MWCNT composites during melting and crystallization. The 110 keV electron irradiation can slow down the amorphous region expansion and the initial melting of lamellae of the LDPE matrix during melting. The 110 keV electron irradiation can slow down the amorphous region shrinkage and inhibit crystal from growing up during crystallization. During melting, MWCNTs can hinder the amorphous and crystalline molecular chains of LDPE from moving, which hinders the LDPE matrix from initially melting, but promotes the melting process after the initial melting has begun. During crystallization, MWCNTs could promote the formation of crystal of the LDPE matrix and inhibit the crystal from growing up.

Radiation hazard and protection for the nuclear weapon terrorism

Effects of electric arc furnace steel slag replacement level, particle size, and curing duration on the mechanical, environmental, and radiation shielding performance of concrete.

Government Regulation Number 45 of 2023 concerning Ionizing Radiation Safety and Radioactive Substance Safety states that every activity related to the use of nuclear energy must pay attention to radiation safety by building and developing a safety culture in all organizational activities. In addition, radiation workers and other personnel related to the use of nuclear energy are required to support the implementation of a safety culture. Based on this, it is essential to conduct periodic evaluations to determine the risk analysis of the implementation of radiation safety in every facility that utilizes radiation, including the Yogyakarta Islamic Hospital (RSIY) PDHI, which utilizes ionizing radiation for patient diagnosis and therapy. The type of research conducted at RSIY PDHI is qualitative research using case study analysis. The research was conducted from March to August 2024. Data was collected in three ways: observation, interviews, and document analysis. The study showed that radiation protection equipment showed consistent results with the "less" category during the six months of observation. Optimization and radiation safety implementation generally received a "good" score, except in June, which showed a decrease to the "less" category. Radiation protection and safety training was consistently in the "less" category. The interview results show several concrete steps have been taken to implement a radiation safety culture. It can be concluded that, although several aspects still need to be monitored and improved, RSIY PDHI has shown a solid commitment to implementing a radiation safety culture. Continuous evaluation and improvement are essential to ensure optimal safety for all parties involved. Keywords: radiation protection, radiation safety, radiation safety culture, assessment and continuous improvement.

There is increasing government and private sector interest in sending astronauts and advanced robotic equipment to the Moon for lunar exploration, space mining, and commerce. Space nuclear technologies, including both radioisotope and fission energy, are enabling technologies that could support such activities through lunar night survival and high-energy activities like space mining. Both NASA’s flagship Artemis program and China’s International Lunar Research Station aim to send astronauts to the lunar surface within a decade, and eventually establish a base. The potential for astronauts from multiple countries and companies to operate near space nuclear systems makes radiation safety an important technical and policy consideration for nuclear system developers and mission planners. However, there is relatively limited norms, standards, or guidance about how to safety site and operate space nuclear systems in proximity to astronauts on planetary surfaces. This paper proposes the development of the “radiation field” concept to represent the radiation emissions from space nuclear systems and facilitate their incorporation in lunar policy and mission planning. It reviews potential dose thresholds for different zones and proposes using the safety zone policy mechanism proposed by the international Artemis Accords to communicate radiation field information. Its findings provide the initial basis for developing radiation safety practices for astronauts on the surface of the Moon and Mars.

In recent years, eye lens exposure among radiation workers has become a serious concern in medical X-ray fluoroscopy and interventional radiology (IVR), highlighting the need for radiation protection education and training. This study presents a method that can maintain high accuracy when calculating spatial dose distributions obtained via Monte Carlo simulation and establishes another method to three-dimensionally visualize radiation using the obtained calculation results for contributing to effective radiation-protection education in X-ray fluoroscopy and IVR. The Monte Carlo particle and heavy ion transport code system (PHITS, Ver. 3.24) was used for calculating the spatial dose distribution generated by an angiography device. We determined the peak X-ray tube voltage and half value layer using Raysafe X2 to define the X-ray spectrum from the source and calculated the X-ray spectrum from the measured results using an approximation formula developed by Tucker et al. Further, we performed measurements using the “jungle-gym” method under the same conditions as the Monte Carlo calculations for verifying the accuracy of the latter. An optically stimulated luminescence dosimeter (nanoDot dosimeter) was used as the measuring instrument. In addition, we attempted to visualize radiation using ParaView (version 5.12.0-RC2) using the spatial dose distribution confirmed by the above calculations. A comparison of the measured and Monte Carlo calculated spatial dose distributions revealed that some areas showed large errors (12.3 and 24.2%) between the two values. These errors could be attributed to the scattering and absorption of X-rays caused by the jungle gym method, which led to uncertain measurements, and (2) the angular and energy dependencies of the nanoDot dosimetry. These two causes explain the errors in the actual values, and thus, the Monte Carlo calculations proposed in this study can be considered to have high-quality X-ray spectra and high accuracy. We successfully visualized the three-dimensional spatial dose distribution for direct and scattered X-rays separately using the obtained spatial dose distribution. We established a method to verify the accuracy of Monte Carlo calculations performed through the procedures considered in this study. Various three-dimensional spatial dose distributions were obtained with assured accuracy by applying the Monte Carlo calculation (e.g., changing the irradiation angle and adding a protective plate). Effective radiation-protection education can be realized by combining the present method with highly reliable software to visualize dose distributions.

Research on radiation sensitive biomarkers and status of radiation safety literacy under low dose irradiation: Radiation biomarkers and radiation safety culture

Radiation protection problems for the space station and approaches to their mitigation

To study cause specific mortality of radiation workers with particular reference to associations between fatal neoplasms and level of exposure to radiation. Cohort study. United Kingdom. 95,217 radiation workers at major sites of the nuclear industry. Cause of death. Most standardised mortality ratios were below 100: 83 unlagged, 85 with a 10 year lag for all causes; 84 unlagged, 86 lagged for all cancers; and 80 for all known other causes, indicating a "healthy worker effect." The deficit of lung cancer (75 unlagged, 76 lagged) was significant at the 0.1% level. Standardised mortality ratios were significantly raised (214 unlagged, 303 lagged) for thyroid cancer, but there was no evidence for any trend with external recorded radiation dose. Dose of external radiation and mortality from all cancers were weakly correlated (p = 0.10), and multiple myeloma was more strongly correlated (p = 0.06); for leukaemia, excluding chronic lymphatic, the trend was significant (p = 0.03; all tests one tailed). The central estimates of lifetime risk derived from these data were 10.0% per Sv (90% confidence interval less than 0 to 24%) for all cancers and 0.76% per Sv (0.07 to 2.4%) for leukaemia (excluding chronic lymphatic leukaemia). These are, respectively, 2.5 times and 1.9 times the risk estimates recommended by the International Commission on Radiological Protection, but 90% confidence intervals are large and the commission's risk factors fall well within the range. The positive trend with dose for all cancers, from which the risk estimate was derived, was not significant. The positive association between leukaemia (except chronic lymphatic leukaemia) was significant and robust in subsidiary analyses. This study showed no association between radiation exposure and prostatic cancer. There is evidence for an association between radiation exposure and mortality from cancer, in particular leukaemia (excluding chronic lymphatic leukaemia) and multiple myeloma, although mortality from these diseases in the study population overall was below that in the general population. The central estimates of risk from this study lie above the most recent estimates of the International Commission on Radiological Protection for leukaemia (excluding chronic lymphatic leukaemia) and for all malignancies. However, the commission's risk estimates are well within the 90% confidence intervals from this study. Analysis of combined cohorts of radiation workers in the United States indicated lower risk estimates than the commission recommends, and when the American data are combined with our analysis the overall risks are close to those estimated by the commission. This first analysis of the National Registry for Radiation Workers does not provide sufficient evidence to justify a revision in risk estimates for radiological protection purposes.

Radiation awareness and protection of patients have been the fundamental responsibilities in diagnostic imaging since the discovery of x-rays late in 1895 and the first reports of radiation injury in 1896. In the ensuing years, there have been significant advancements in equipment that uses either x-rays to form images, such as fluoroscopy or computed tomography (CT), or the types of radiation emitted during nuclear imaging procedures (e.g., positron emission tomography [PET]). These advancements have allowed detailed and indispensable evaluation of a vast array of disorders. In fact, in 2001, CT and MRI were cited by physicians as the most significant medical innovations in the previous 3 decades. Rapid technological advancements in the last decade with CT, especially, have required imaging professionals to keep pace with increasingly complex technology to derive the maximum benefits of improved image acquisition and display techniques, in essence, the improved quality of the examination. It has also been challenging to fulfill the fundamental responsibilities of safety during this period of rapid growth (e.g., radiation protection, management of the risk of additional interventions driven by incidental findings, performing studies that were not indicated). The purpose of this paper is to define critical issues pertinent to ensuring patient safety through the appropriate assessment, recording, monitoring, and reporting of the radiation dose from CT.

본 연구의 목적은 방사선의 사업적 이용에 따른 방사선발생장치 또는 방사성동위원소 등(이하 방사성동위원소 등)을 운용하는 방사선작업종사자를 대상으로 방사선안전관리와 관련된 지식의 설문 조사하고 이를 체계적으로 추이분석 함으로서 방사선 이용시설 등의 방사선안전 문화를 정착시키기 위함에 있다. 연구 방법은 2011년 08월 01일 부터 09월 05일 까지 861 명의 방사선 종사자를 대상으로 설문 조사를 하였다. 분석 방법으로 설문 응답자의 일반적인 특성과 기관정보는 빈도 분석을 하였으며 방사선안전관리에 대한 지식 수준은 평균과 표준편차를 구하여 각각 비교하였다. 분석 결과 작업 종사자의 방사선 안전 관리에 대한 지식 조사에서는 종사자 모두 높은 수준으로 평가 되었다. 결론적으로 방사선 작업종사자들의 방사선 안전관리와 관련하여 보다 다양한 요인들에 대한 연구들이 수행되어야 하며 작업종사자들의 의식을 높이기 위해서 시기적절한 교육이 필요할 것으로 사료되며, 지속적으로 방사선 작업종사자들을 관리함으로써 효율적인 방사선이용이 될 수 있는 기반이 확립될 것으로 사료된다. The purpose of this study was examine via a survey the knowledge related to radiation safety management (RSM) among radiation workers who operated or used a radiation generator or radioactive isotopes (radioactive isotopes, etc. hereinafter) for industrial use and to systematically analyze the changes in the survey results in order to promote a radiation safety culture for facilities where radiation is used. We administered a questionnaire to 861 radiation workers in the period from August 1 to September 5, 2011. As for the analysis method, a frequency analysis was made for the general characteristics and organization information of survey respondents, while the average and standard deviation were calculated and compared for the knowledge level of the RSM. According to the analysis results, the knowledge level of the RSM was evaluated to be high in all of the radiation workers. In conclusion, it is required to conduct a study on various factors in regards to the RSM among radiation workers. This can contribute to establishing educational programs in a timely manner to increase the awareness of safe and efficient use of radioactive materials and equipments by radiation workers.

Radiation shielding is a critical practice involving the utilization of materials or barriers to safeguard against ionizing radiation by absorbing, scattering, or blocking the radiation. Its primary objective is to curtail exposure and mitigate potential health risks associated with radiation. In diverse fields like medicine, industry, and nuclear applications, radiation shielding materials play a pivotal role in ensuring the safety of individuals and equipment, contributing significantly to the maintenance of secure environments. This study focuses on characterizing materials for radiation shielding, particularly of Platinum group alloys in varying compositions with hydrogen. Using the Klein-Nishina (KN) formula, the investigation calculates electronic cross-sections (ECS), total mixture cross-section (TMCS), and mass attenuation coefficient (MAC) for different weight percentages of Platinum group alloys (0.1 to 0.6) when exposed to γ-ray photons of various energies. The outcomes emphasize the strong dependence of these cross-sections and MAC on photon energy and the charge number of the material, revealing a decrease with increasing photon energy and an increase with the charge number to mass number ratio (Z/A). The research underscores that fundamental parameters such as charge number, photon energy, and Z/A can be manipulated to enhance the utility of these elements in radiation shielding, protection, dose measurements, and imaging. The study's implications extend to the optimization of Platinum Group alloy compositions, offering insights for the development of tailored materials with enhanced shielding effectiveness in radiation protection and safety applications.

Objective To measure the personal radiation dose for medical staff in PET/CT center and to offer the reference data for clinical radiation protection. Methods Apply TLD methods to monitor the radiation workers’ dose of 2 PET/CT center in Shandong Province. Chest dosimeter for body, lens dosimeter for eyes and ring dosimeter for fingers during distribution and injection. Results Higher dose of the procedures are distribution, injection, positioning, drug preparation and scanning in descending order. Eye dose are 0.38 mSv/a and 0.27 mSv/a for distribution and injection; finger dose are 43.90 mSv/a and 17.75 mSv/a for distribution and injection. The average dose for one scanning can be calculated by workload. Conclusion Under the workload in the research, the doses received by staff members do not exceed the annual limit for professional persons. When the workload is dramatically higher per year, the dose may exceed the national radiation safety standards (GBSS) on occupational annual dose limit. Key words: Positron-emission tomography; Tomography, X-ray computed; Radiation dosage; Radiation protection; Fluorodeoxyglucose F18

A retrospective cohort mortality study was conducted of workers engaged in nuclear technology development and employed for at least 6 months at Rocketdyne (Atomics International) facilities in California, 1948-1999. Lifetime occupational doses were derived from company records and linkages with national dosimetry data sets. International Commission on Radiation Protection (ICRP) biokinetic models were used to estimate radiation doses to 16 organs or tissues after the intake of radionuclides. Standardized mortality ratios (SMRs) compared the observed numbers of deaths with those expected in the general population of California. Cox proportional hazards models were used to evaluate dose-response trends over categories of cumulative radiation dose, combining external and internal organ-specific doses. There were 5,801 radiation workers, including 2,232 monitored for radionuclide intakes. The mean dose from external radiation was 13.5 mSv (maximum 1 Sv); the mean lung dose from external and internal radiation combined was 19.0 mSv (maximum 3.6 Sv). Vital status was determined for 97.6% of the workers of whom 25.3% (n = 1,468) had died. The average period of observation was 27.9 years. All cancers taken together (SMR 0.93; 95% CI 0.84-1.02) and all leukemia excluding chronic lymphocytic leukemia (CLL) (SMR 1.21; 95% CI 0.69-1.97) were not significantly elevated. No SMR was significantly increased for any cancer or for any other cause of death. The Cox regression analyses revealed no significant dose-response trends for any cancer. For all cancers excluding leukemia, the RR at 100 mSv was estimated as 1.00 (95% CI 0.81-1.24), and for all leukemia excluding CLL it was 1.34 (95% CI 0.73-2.45). The nonsignificant increase in leukemia (excluding CLL) was in accord with expectation from other radiation studies, but a similar nonsignificant increase in CLL (a malignancy not found to be associated with radiation) tempers a causal interpretation. Radiation exposure has not caused a detectable increase in cancer deaths in this population, but results are limited by small numbers and relatively low career doses.